Problem with Clack WS1-CS

I have a 4-year-old softening system with a Clack WS1-CS valve. It regenerates about every 2 weeks without a problem. However, between regenerations, water continuously leaks from the Clack valve through the brine tubing into the brine tank, at a rate of about 0.4 gallons per day. By the time the next regeneration is due, there's 5-6 gallons of excess water in the tank. Then it pre-fills for the brining cycle and adds even more water. When all this water is suck out during regeneration, it takes 3 times the normal salt load with it. So I'm using salt at an excessive rate. I assume the problem is a leaky seal somewhere inside the valve. Could it be anything else? Is this something that a homeowner can repair himself?

If the dealer is still in business you can get a new complete piston (that is both the brine and main pistons) and a new stack (seals and spacers part). They are the only cause of your problem. Don't replace just one or the other.

If the dealer is not in business then call Clack and talk to Bob Bishop to find a dealer or they can send the parts to you although those parts are not under warranty because they call them 'consumables".

Here is a decent video of how to rebuild the WS1 valve. Leaking to the drain is usually a piston/seal spacer kit issue. Call the company that sold it to yiou, they should be willing to sell you the kit.

I guess you missed the part where he has water flowing to the brine tank, not to drain.

CAUTION: Anyone using the video to replace the piston and stack in a Clack valve.... you must follow the instructions in the manual as you screw in the drive end cap. Otherwise you can ruin your new stack or prevent the valve from working correctly.

Also, unless you like spending money needlessly, there is no need to replace o-rings unless there is visible damage.

And IIRC, the round full circle wrench is the latest version, the half circle is the original version.